1. Field of the Invention
The present invention relates to aircraft surface guidance systems (SGS) and, in particular, to a user interface comprising a menu structure for quickly selecting a desired taxi path for an aircraft at an airport.
2. Technical Background
There is considerable interest in enhancing the field of surface guidance for aircraft. After an aircraft lands on a runway at an airport, the next step is to taxi the aircraft to a desired destination such as a passenger loading/unloading gate. A pilot can easily become confused or lost amid the many runways, taxiways, ramps, and buildings that make up an airport. The problem is more significant at large airports and is particularly significant at night when the multitude of lights can make it more difficult to taxi the aircraft to the desired destination.
Efficient taxi operations save time and money. With airports becoming more crowded, aircraft often spend considerable time taxiing between runways and gates. Taxi time is even longer if the pilot makes a wrong turn, becomes lost, or blunders onto the wrong runway or taxiway. In addition, a wrong turn or navigation blunder can cause delays for other aircraft at the airport.
A main feature of an airport surface guidance capability is the presentation of an airport map that is readily available to the pilot. One conventional approach to present such a map is on a head-down display (HDD) that is displayed in the forward field of view of the pilot. The pilot typically enters or selects a taxi path that has been approved by ground controllers. The display then indicates the current aircraft position and the taxi path is shown overlaid on the airport map. The display gives a pilot situational awareness of where the aircraft is relative to the selected taxi path. A key aspect to a practical avionics implementation for surface guidance must generally include a user interface for the intuitive and rapid entry of air traffic control (ATC) radio communicated taxi instructions into the on-board SGS system by the pilot or crew.
To make surface guidance operationally acceptable, it is imperative to provide the aircraft crew with an intuitive and rapid means to insert taxi instructions into the surface guidance system and to integrate that operation with the normal aircraft operations that are familiar to the pilot/crew. Prior attempts to implement surface guidance separated the taxi planning step from the enroute planning process. This typically creates a significant training burden for the airlines or aircraft fleet operator.
Any aircraft taxi planning system should be adequate not only to accomplish the task of receiving taxi instructions, but to also make the user interface intuitive such that training time is minimized. It is also desirable to facilitate rapid taxi route selection and minimize entry errors.
The continuing goal, therefore, is to find ways to reduce costs, reduce taxi errors, minimize training, reduce taxi time, and improve airport efficiency.
To address the goals stated above and other goals, the inventive taxi planning system includes a unique user interface and a database comprising information descriptive of the runways and taxiways for an airport. The invention integrates the taxi planning process with the enroute planning process and uses similar procedures. This creates an intuitive user interface and further creates an operationally acceptable implementation of taxi planning that significantly reduces crew training time and costs. The use of data entry techniques in accordance with the invention minimizes the time required to enter taxi planning commands and also minimizes taxi planning errors.
According to one aspect of the present invention, the taxi planning system is integrated as an extension of the flight management system (FMS) which provides the enroute planning function for the aircraft. The page formats of the invention are preferably an extension of the page formats used by the FMS for enroute planning, and is therefore intuitive and easily learned by pilots and crew.
In another aspect of the invention, selection menus are used to simplify taxi route entry and reduce errors. The invention is provided with the current location of the aircraft (e.g., a runway or gate). This information is previously entered by the pilot or is received from another aircraft system. The system also is preferably provided with a destination (e.g., runway 27R or gate A25). Using this preliminary information, the invention looks up the valid taxi selections associated with the current location and displays them to the pilot as a menu. As the pilot selects a leg of the taxi path, the screen is scrolled up and a new menu of valid taxi leg selections is presented. The process proceeds quickly until the taxi plan is complete. In another embodiment, predefined standard routes are stored in memory and are made available for selection. In yet another embodiment, a predefined standard taxi route is received from ATC via a data link.
Yet another aspect of the invention is the database structure used to implement the invention. The database structure preferably uses a linked list that is flexible for implementing various airport configurations. The database can be updated frequently without the need to alter program software. More preferably, the invention uses a linked list created from two data tables.
It is clear that the invention is a significant improvement over the prior art systems. Further, those skilled in the art recognized that the invention is not limited to use with an FMS. Other processors, display screens, and data entry devices may be used to practice the invention.
Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described in the detailed description which follows, the claims, as well as the appended drawings.
It is to be understood that the foregoing description is exemplary of the invention only and is intended to provide an overview for the understanding of the nature and character of the invention as it is defined by the claims. The accompanying drawings are included to provide a further understanding of the invention and are incorporated and constitute part of this specification. The drawings illustrate various features and embodiments of the invention which, together with their description serve to explain the principals and operation of the invention.